Summary
Mobs spawned by the randomspawn system rarely spawn on top of blocks and instead spawn 1 or 2 blocks below the surface, either half submerged or fully. This was not an issue on 1.20.
Steps to reproduce
https://paste.morose.dev/p/3M08SY.yml This config is used by me to get the results, config has been untouched since at least half a year, after updating to 1.21 the issues came up
Current behavior
Mobs spawning around players are spawning inside of blocks and die
Intended correct behavior
Mobs should not spawn inside of blocks...
Server log file
Provide a link to a Pastebin paste with a copy of your server's latest.log file from startup to "Done!" AND includes a player connecting.
https://paste.morose.dev/p/hs7wXX.log
Provide a link to a Pastebin paste with an excerpt of your latest.log file that includes debug output where you trigger the bugged behavior.
Proposed fixes
Describe what you think the issue or any potential fixes may be.